The subsection Spin_Interactions of the Collision_Term section can be used to modify spin-interactions. The allowed keys are: On, which includes all available spin interactions and Off, which excludes all spin interactions.

For example:

Collision_Term:
    Spin_Interactions: On

Spin_Interactions — string, optional, default = "Off"

Whether or not to enable spin interactions in binary collisions.

Note: So far we only include a spin flip in elastic scatterings.